Wireless technologies are of great importance in today's marketplace, and will continue to be so in the future. In wireless technologies, one figure of merit is a degree of impedance “match” between an antenna and amplifier of a wireless device.
A proper input matching has a great influence on both a gain and a noise factor of an amplifier. Components of wireless devices, such as surface acoustic wave (“SAW”) filters, work properly only when a correct impedance is presented at its terminals. Typically, the amplifier should be able to maintain its performance even for a voltage standing wave ratio (“VSWR”) of 3:1.
However, the input impedance, as seen by the wireless device, can change over time. Therefore, an impedance mismatch occurs. This impedance mismatch can occur due to an aging antenna, a change in an orientation of the antenna, or other things.
However, there are drawbacks with prior art approaches of compensating for impedance mismatches. For instance, one or a series of physical capacitors can be placed between a gate of the amplifier and ground, or various couplings of inductors between the gate of the transistor and an input of a device under test can be placed between a gate of the amplifier and ground to achieve impedance matching. However, significant complexity and noise of the switches can be added in this aspect, and significant integrated circuit area can be consumed.
Accordingly, what is needed in the art is a system and a method to match input impedances that addresses the drawbacks of the prior art.